The invention relates to a process for preparing a C3-6 (hydro)fluoroalkene comprising dehydrohalogenating a C3-6 hydro(halo)fluoroalkane in the presence of a zinc/chromia catalyst, wherein the C3-6 (hydro)fluoroalkene produced is isomerized in the presence of the zinc/chromia catalyst.

A method of purification of crude cis-2-alkenoic acid by thermal separation, comprising wiped-film evaporation or vacuum distillation of the crude cis-2-alkenoic acid, under a temperature-reduced pressure profile whereby isomerization of cis-2-alkenoic acid into trans-2-alkenoic acid is minimized.

A method of purification of crude cis-2-alkenoic acid by thermal separation, comprising wiped-film evaporation or vacuum distillation of the crude cis-2-alkenoic acid, under a temperature-reduced pressure profile whereby isomerization of cis-2-alkenoic acid into trans-2-alkenoic acid is minimized.